JPH0979718A - Ice making device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable transparent water having scarcely deposition of mineral substances to be produced. SOLUTION: During an ice making operation, an upper surface of an ice making pan 12 is covered by a lid 14, water surface of water supplied to an ice making block 20 is heated by a heating means 24 arranged at the ice making pan 12. Water is condensed at a bottom part of the ice making block 20, e.g. a part not heated by the heating means 24 so as to cause gaseous substance in water to be discharged forcedly out of the water surface of the heated part by a convection of the water generated by this heating operation. Then, lastly, the water at the heated part is condensed to attain transparent water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice making device,
In particular, the present invention relates to an ice making device that can suitably make transparent ice.

[0002]

2. Description of the Related Art Conventionally, in an automatic ice making device arranged in a domestic refrigerator or the like, water supplied to an ice making tray made of plastic or metal is solidified at once in a room at a low temperature of about -18 ° C. In this case, in each ice making block of the ice making tray, first, as shown in FIG.
1 layer is formed, and this ice layer 101 grows, and
As shown in 1 (b) and (c), the inside of the ice 101 is 0 ° C.
The uncoagulated water 102 is trapped. The gas component dissolved in the water is the same as the ice 101 grows.
Are extruded from the growing portion of the water, form bubbles 103, and precipitate in the unsolidified water 102. However, uncoagulated water 102
Is shielded by a layer of surrounding ice 101, so that the bubbles 103 are solidified while being confined in the ice 101, and as shown in FIG. , White turbid portion 1 caused by bubbles 103 inside
Have 05. Such cloudy opaque ice 104 is
Not only does it look bad, but it also has the disadvantage that it melts faster than so-called clear ice, which has no cloudy parts.

Therefore, conventionally, as shown in FIG. 12, a lid 11 capable of heating the upper portion of an ice tray 110 with a heater 111.
2, the cold air 113 is blown onto the lower surface of the ice tray 110 to solidify the water 114 therein from the lower portion of the ice tray 110, and the ice tray 110 is vibrated in the horizontal direction 115.
By adding, the gas component dissolved in water is forcibly released to the outside to obtain transparent ice.

[0004]

However, the vibration 1
When 15 is added to release the gas component, the mineral component dissolved in the water is also precipitated as crystals at the same time. Therefore, as shown in FIG. 117 is formed. The mineral crystal layer 117 has a drawback that when the ice 116 is melted, it floats in water, a beverage, or the like, and makes the water, the beverage, or the like look cloudy.

Therefore, in view of the above points, an object of the present invention is to provide an ice making device capable of obtaining transparent ice with almost no precipitation of minerals.

[0006]

An ice making device according to claim 1 of the present invention is an ice making device which supplies water to an ice making plate composed of a plurality of ice making blocks to make ice for each ice making block. And a heating means which is provided in the ice tray and heats the upper portion of the water supplied to the ice making block.

According to another aspect of the present invention, there is provided an ice making device, wherein water is supplied to an ice tray made up of a plurality of ice making blocks to make ice in each ice making block, the ice making device is provided in the ice making tray and is supplied to the ice making block. The heating means for heating the upper part of the water, and a lid for covering a part of the upper surface of the ice tray, the lid being arranged in proximity to and above the water surface of the portion heated by the heating means. It is what

The ice making device according to claim 3 is the ice making device according to claim 1 or 2.
In the above, the heating means is attached to the back surface of the ice tray.

The ice making device according to claim 4 is the ice making device according to claim 1 or 2.
In the above, the heating means is arranged close to the water surface of the water supplied to the ice making block.

The ice making device of claim 5 is the ice making device of claim 1 or 2.
In the above, the ice making blocks are arranged in two or more rows, and the heating means is arranged on a partition wall that partitions the rows.

According to a sixth aspect of the present invention, there is provided an ice making device in which water is supplied to an ice tray made up of a plurality of ice making blocks to make ice in each of the ice making blocks. , A heating means provided on the lid and heating a part of the upper surface of the ice tray.

According to a seventh aspect of the present invention, there is provided the ice making device according to the sixth aspect, wherein the ice making blocks are arranged in two or more rows, the lid covers a partition wall separating the rows of the ice making blocks, and the heating means. However, it heats the upper surface of the water in contact with the partition wall.

The ice making device according to claim 8 is the ice making device according to claims 1, 2, and 6.
In any one of 1) to (3), at the time of ice making, while cooling the ice making tray, the time when the operation of the heating means is started is detected to operate the heating means, and the water supplied to the ice making block is When the solidification is detected except for the portion close to the heating means, the operation of the heating means is stopped, and the cooling means is continued to complete the ice making.

[0014]

In the ice making device according to the first aspect of the present invention, at the time of ice making, the top surface of the ice making plate is covered with a lid, and the water in the upper part of the ice making block is heated by the heating means provided in the ice making plate. Begins to solidify from other parts except the heated part which is the part heated by the heating means, and from there solidification proceeds toward the heated part. The gas component dissolved in water is pushed out from the ice growth point as the ice grows,
Due to the convection caused by the temperature difference of the water, it is forcibly collected from the other portion of the ice making block to the water surface of the unsolidified heated portion and discharged from there. in this way,
Gaseous components dissolved in water are forcibly released from the water surface to the outside, and finally the water in the heated part on the top of the ice making block is solidified, so there is no formation of cloudy parts due to bubbles inside the ice. .

In the ice making device of the second aspect, at the time of ice making, the heating means provided in the ice making tray heats the water on the upper portion of the ice making block, and the upper portion of the heating portion is covered with the lid. Similar to the device, the water in each ice making block begins to solidify from other parts except the heated part, and from there, solidification proceeds toward the heated part. Then, due to the temperature difference of the water, convection occurs in the ice making block, and the gas component in the water is forcibly discharged from the water surface to the outside by this convection. Therefore, a cloudy portion due to bubbles is not formed inside the ice. In addition, in this device, the water surface of the portion not covered by the lid quickly solidifies together with the water at the bottom of the ice making block, so that the ice making time can be shortened.

In the ice making device of the third aspect, since the heating means is attached to the back surface of the ice tray, the heating means can be easily arranged.

In the ice making device of the fourth aspect, since the heating means is arranged close to the water surface of the water supplied to the ice making block,
The water surface adjacent to the heating means is effectively heated, and the unsolidified portion for releasing the gas component can be reliably formed on the water surface.

In the ice making device according to the fifth aspect of the present invention, since the heating means is arranged on the partition wall that divides the rows of the ice making blocks arranged in a plurality of rows, the heating means is provided on the outer peripheral wall of the ice making tray. , Is less susceptible to the cold air flowing around the ice tray, and the input to the heating means can be reduced.

In the ice making apparatus according to the sixth aspect, at the time of ice making, a part of the upper surface of the ice making tray is covered with the lid, and the water below the lid is heated by the heating means provided on the lid. 1
Similar to the ice making device of, the water in each ice making block begins to solidify from other parts except the heating part by this heating means,
From there, solidification proceeds toward the heated part. Then, the gas component in the water is forcibly discharged from the water surface to the outside by the convection generated in the ice making block due to the temperature difference of the water. Therefore, a cloudy portion due to bubbles is not formed inside the ice. In addition, in this device, the water surface of the portion not covered by the lid quickly solidifies together with the water at the bottom of the ice making block, so that the ice making time can be shortened.

In the ice making device according to the seventh aspect of the present invention, since the water surface in the vicinity of the partition wall that partitions the rows of the ice making block is heated by the heating means, compared to the case where the lid is provided so as to cover the outer peripheral wall of the ice tray. , The heated part is less affected by the cold air flowing around the ice tray.

According to the eighth aspect of the present invention, in the ice making device, when the ice making device detects the time when the operation of the heating means is started, such as when the water temperature in the ice making block becomes 0 ° C. after the water is supplied, the heating means is Start to work. After that, when the water in the ice making block is solidified except for the portion close to the heating means, the heating means stops its operation, the water in the ice making block is completely solidified, and the solidified ice is further cooled to make ice. Is completed. As a result, the water in the ice making block can be quickly lowered to the freezing temperature, and the heated portion can be quickly solidified after the gas component is released. Therefore, the ice making time can be shortened.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The first embodiment of the present invention will be described below.
The ice making device 10 according to the example will be described with reference to the drawings.

The ice making device 10 is an automatic ice making device arranged in a freezer compartment of a domestic refrigerator, and as shown in FIG. 1, the ice making device 12 arranged horizontally and the upper surface of the ice making device 12 are covered. It comprises a lid 14 and a mechanical part 16 for supporting the ice tray 12 and the lid 14 and controlling the operation thereof.

The ice tray 12 is a plastic deformable tray horizontally supported by a support member 18 extending rearward from the machine section 16, and has a thin rectangular container shape with an upper surface opened, and a plurality of internal portions. Individual ice blocks 20,2
It is divided by 0 ... The ice making block 20 is
As shown in FIG. 3, four in the front-back direction are formed in two rows in the left-right direction, for a total of eight. As shown in FIG. 2, a heater 24 for heating is arranged on the back surface side of the ice tray 12 on the partition wall 22 that partitions the rows of the ice making blocks 20 arranged in two rows.

The heater 24 is arranged in the upper part of the partition wall 22 so as to reciprocate in the front-rear direction. That is, the two terminals 2 arranged at the front end of the ice tray 12
Of the Nos. 5 and 25, they extend rearward from one terminal 25, are folded back at the rear end of the ice tray 12, and are connected to the other terminal 25. The heaters 24 are arranged side by side so as to heat the water that comes into contact with the upper portions of the partition walls 22 of the left and right ice making blocks 20, 20 on the outward path and the return path, respectively. The heater 24 is in contact with the inner surface of the partition wall 22 slightly below the water surface of the water 46 supplied to the ice making block 20. The terminals 25, 25
Is connected to an external power source (not shown) and a control unit 28 arranged in the machine room 16.

The inside of the partition wall 22 is filled with a heat insulating material 26 that covers the heater 24, which insulates the heater 24 from the surrounding cool air and is heated by the heater 24. 20 The upper part is shielded from the surrounding cold air.

A temperature sensor 30 for detecting the temperature of the bottom of the ice tray 12 is attached to the lower surface of the ice tray 12.
The temperature sensor 30 is provided in the ice making block 2 near the center.
It is arranged on the lower surface of the bottom plate 0 and is connected to the control unit 28.

The ice tray 12 is rotatably supported by a support member 18 connected to the control unit 28 about a horizontal axis extending in the front-rear direction at the center of the ice tray 12, and
A twisting deformation is applied during this rotation.

The lid 14 is a rectangular plastic plate member horizontally supported by a supporting member 32 extending rearward from the machine section 16. The lid 14 covers the entire upper surface of the ice tray 12 over the entire surface to prevent cold air from surrounding. It is configured to shut off. The inside of the lid 14 is filled with a heat insulating material 34. The lid 14 moves up and down by the support member 32 connected to the control unit 28 to cover the upper surface of the ice tray 12 so as to be openable and closable.

Reference numeral 36 denotes a changeover switch arranged on the front surface of the mechanical section 16, which is connected to the control section 28 and switches between a transparent ice making mode for making transparent ice and an opaque ice making mode for making opaque ice. Do.

Reference numeral 38 denotes a water supply pipe for supplying water into the ice tray 12, which is arranged behind and above the ice tray 12. Reference numeral 40 denotes a cold air duct that blows cold air to the lower portion of the ice tray 12, which is arranged behind the ice tray 12 and maintains the ambient temperature of the ice making device 10 at about -18 ° C. Reference numeral 42 denotes an ice storage container that stores the ice made by the ice tray 12, and is arranged below the ice tray 12. Reference numeral 44 denotes an ice storage detection lever that detects the amount of ice stored in the ice storage container 42 and extends rearward and downward from the mechanical portion 16.

Next, the operation of the ice making device 10 will be described separately for the above two ice making modes.

First, the control unit 2 in the transparent ice making mode.
8 will be described.

With the lid 14 open, the water supply pipe 38
The ice tray 12 is supplied with water, and after the water is supplied, the lid 14 is lowered to close the lid.

When the temperature detected by the temperature sensor 30 reaches 0 ° C., energization of the heater 24 is started and the ice tray 12
The vicinity of the water surface of the water 46 supplied to is heated.

When the temperature detected by the temperature sensor 30 reaches −4 ° C., the lid 14 is raised and the heater 24
Stop supplying power to

The temperature detected by the temperature sensor 30 is −13 ° C.
When it becomes, it is judged that the ice making is completed, and the ice tray 12
Is rotated and twisted to drop the ice made in each ice making block 20 into the ice storage container 42. Then return to again.

Next, in this transparent ice making mode,
The solidified state of ice will be described with reference to FIGS.

The water 46 supplied to the ice tray 12 is cooled by the cold air flowing in the lower portion of the ice tray 12 and its temperature is lowered. When the temperature of the bottom of the ice making block 20 reaches 0 ° C., the heater 24 heats the water in the portion near the partition wall 22 above the ice making block 20 (hereinafter referred to as the heating portion). The water at the bottom of the ice making block 20 gradually begins to solidify at 0 ° C., which is the freezing point, as shown in FIG. Here, in the heating portion, the heater 24 heats the heating portion, and the lid 14 prevents the cold air from directly contacting the heating portion. Therefore, as shown in FIGS. 4A and 4B, the solidification starts from the bottom of the ice making block 20, and a layer of ice 47 gradually grows upward.

At this time, the gas component dissolved in the water 46 is pushed out from the growth point of the ice 47 as the ice 47 grows, and is forcibly collected from the bottom of the ice making block 20 to the heating portion, It is released from the water surface of this heated portion to the outside.

When the bottom of the ice making block 20 is solidified, the temperature detected by the temperature sensor 30 begins to drop, as shown in FIG. Then, at the stage shown in FIG. 4 (b) where the water in the other portion excluding the heated portion has solidified, the temperature detected by the temperature sensor 30, that is, the temperature at the bottom of the ice making block 20, has dropped to about -4 ° C. . At this stage, the heating of the heater 24 is stopped, and the water in the heated portion which remains without being solidified finally solidifies to a transparent state where there is no cloudiness and precipitation of minerals due to bubbles. As shown in FIG. 4 (c),
In some cases, a cloudy portion 48 due to a slight amount of bubbles may be generated in the finally solidified heated portion, but the appearance and the melting rate thereof are greatly improved as compared with the conventional large portion generated in the ice.

After the coagulation is completed in this way, it is further cooled and ice making is completed when the temperature of the ice drops to -13 ° C., and clear ice with almost no cloudiness or precipitation of minerals is obtained.

Here, the mechanism of releasing the gas component at this time will be described in detail.

The above-mentioned heating portion is cooled by the lid 14 and is heated by the heater 24 so that the ice making block 20 is heated.
The water temperature is higher than the other parts. That is, the water temperature is 0 ° C. in other parts such as the bottom, but the temperature is higher than 0 ° C. in this heated part. Due to the temperature difference between the heated portion and the other portion, a difference in water density occurs between them. Then, as shown in FIGS. 4 (a) and 4 (b), convection occurs in which water in the heated portion having a high density flows downward, and water in the other portion having a low density flows toward the upper and lateral heating portions. It

Due to this convection, the gas component generated from the ice-growing part of the other part is taken into the convection water and forcedly sent to the heating part, where the melting limit exceeds the melting limit, It is released from the surface of the water into the air.

As described above, since the gas components generated in the other parts except the heated part are forcibly sent to the heated part by the convection of water and released into the air, even if the ice growth rate is high, The bubbles can be well released into the air. Therefore, the ice layer growth rate (Fig. 4 (a)) is the same as in the case where transparent ice was obtained by solidifying very slowly in the past.
In the above, even if the growth thickness of the ice layer shown as D per hour) is not set to 2 to 3 mm / h or less, transparent ice is formed at an ice layer growth rate of 4 mm / h or more (for example, 4 to 10 mm / h). Obtainable.

By releasing by convection in this way, harmful volatile components (chlorine,
Trihalomethane, chloroform, bromodichloromethane, dibromochloromethane, etc.) are also released, so safe ice can be obtained.

Next, the operation and ice-making state of the controller 28 in the opaque ice-making mode, which is another ice-making mode, will be described.

The control section 28 controls so that the heater 24 is not energized. Then, water is supplied from the water supply pipe 38 to the ice tray 12 with the lid 14 opened, and after the water is supplied, the lid 14 is controlled to be held open.

Therefore, the cool air from the cool air duct 40 is
It is sprayed not only from below the ice tray 12 but also from above.
The water supplied into the ice tray 12 is rapidly frozen, and solidifies from the surroundings, as shown in FIG. 11, to a state having a cloudy portion inside.

The temperature detected by the temperature sensor 30 is -1.
When the temperature reaches 3 ° C., it is determined that the ice making is completed, and the ice tray 12 is rotated and twisted to drop the ice produced in each ice making block 20 into the ice storage container 42. As a result, cloudy opaque ice is obtained.

In this way, by providing the changeover switch 36,
When normal opaque ice is obtained by switching between the two ice making modes, a large amount of ice can be obtained in a short time by increasing the ice making speed.

As described above, in the present ice making device 10, the gas component in water is forcibly released from the water surface by the convection generated in the ice making block 20, and the water surface is quickly solidified after the release, so that the transparent ice is It can be made in a short time. In addition, since no mechanical external force such as vibration is applied, minerals are hardly deposited, and a complicated mechanical structure for vibration is not necessary, so there is no noise or vibration due to machine operation, and further failure does not occur. Unlikely to occur. Also,
By the heater 24, one side of the rectangular water surface, that is, the partition wall 2
Convection is smooth because heating is applied only from the side of contact with 2. Further, since only one side is heated, the solidification of water starts not only from the bottom of the ice making block 20 but also from the side on the opposite side facing the one side, so that compared to the case of heating the entire water surface. Fast solidification rate. Further, since the portion heated by the heater 24 is located on the side of the partition wall 22, it is unlikely to be affected by the cold air flowing around the ice tray 12, so that the input to the heater 24 can be reduced.

In the above-mentioned transparent ice making mode,
The heater 24 may be energized at the same time as the water supply or slightly before or after the water supply. However, immediately after water supply,
Since the water temperature has not reached the freezing temperature yet, the ice tray 12
Alternatively, it is preferable to start energization before and after the water temperature in the ice tray 12 reaches 0 ° C., because the entire ice making time can be shortened.

The temperature at which the power supply to the heater 24 is stopped is the bottom temperature of the ice making block 20 at the stage when water is solidified except for the heated portion, as shown in FIG. 4B. The temperature at that time can be appropriately determined depending on the size of the ice making block 20 and the like. Note that normally, −
It is determined in the range of 2 to -5 ° C.

When the temperature sensor 30 detects the time when the heater 24 is energized or de-energized, the water temperature in the ice tray 12 is detected even if the temperature of the ice tray 12 is detected. Good.

Further, these timings may be detected not by the temperature sensor 30 but by the elapsed time from the start of ice making. That is, the time from the start of ice making to the energization and de-energization is set in advance (for example, 1
It is also possible to detect this time using a timer and stop or energize the heater 24 when the set time is reached. Further, such temperature detection and time detection may be combined for control.

In the transparent ice making mode, the lid 14 is used.
While the energization of the heater 24 was stopped while the electric current was raised, the lid 14 may be raised before and after the energization is stopped.
The lid does not necessarily have to be raised, ie it may remain closed.

Next, the ice tray 12 in this first example
An example of the modification will be described with reference to FIG.

In this case, the heater 24 is arranged inside the outer peripheral flange 13 which is folded downward on the outer periphery of the upper surface of the ice tray 12. That is, the heater 24 is arranged on the back surface of the upper portion of the ice tray 12 over the entire circumference of the ice tray 12. The inside of the flange 13 is filled with a heat insulating material 26 that insulates the heater 24 from cold air outside.

Next, an ice making device according to the second example will be described with reference to FIG.

The second example is different from the above-described first example in the structure of the lid that covers the ice tray 12. Lid 50 in this example
Is a part of the upper surface of the ice tray 12 so that the water surface in the vicinity of the partition wall 22 of the ice making block 20 which is heated by the heater 24 is shielded from the surrounding cool air, and the cool air enters the other part of the water surface. It is configured to cover. That is, the lid 50
Is composed of a heat insulating portion 52 that shields the water surface of the portion heated by the heater 24 from cold air, and a rectangular frame body 54 that supports the front and rear ends of the heat insulating portion 52. The heat insulating part 52 is disposed above the partition wall 22 over the entire length thereof, is filled with the heat insulating material 34 inside, and is provided with a recess 56 at the bottom for accommodating the upper end of the partition wall 22. The left and right lower end surfaces of the heat insulating portion 52 located on both sides of the recess 56 are close to the water surfaces of the heated portions of the left and right ice making blocks 20, 20, as shown in FIG. 7B. The frame 54 abuts the outer peripheral flange 13 of the ice tray 12 over the entire circumference thereof, and the heat insulating portion 5
Support 2.

As described above, since only the portion heated by the heater 24 is covered by the lid 50, the open air portion which is not covered by the lid 50 is directly contacted with the cold air, and the ice making block 20.
Solidification begins almost at the same time as the bottom. Therefore, as compared with the above-mentioned first example, the time required for solidifying the other portion excluding the heated portion is shorter.

Next, a modified example of the ice making device of the second example will be described with reference to FIGS.

In the modification shown in FIG. 8, the heat insulating portion 5 of the lid 50 is used.
No recessed portion 56 is provided on the bottom portion of No. 2. Further, the upper end portion of the partition wall 22 of the ice tray 12 is extended upward, and the upper surface thereof abuts the lower surface of the heat insulating portion 52.

By contacting the heat insulating portion 52 and the partition wall 22 in this manner, the passage of cold air below the heat insulating portion 52 is completely eliminated, and the portion heated by the heater 24 is more effectively removed from the cool air. It can be insulated and therefore has high heating efficiency.

In the modified example shown in FIG. 9, the ice tray 12 has a heater 24 provided on the outer peripheral flange 13 described above with reference to FIG. The lid 50 does not include the frame 54,
The heat insulating part 52 is formed in a rectangular frame shape. The heat insulating portion 52 is configured to contact the outer peripheral flange 13 of the ice tray 12, and the lower surface thereof is close to the water surface of the portion heated by the heater 24 so as to shield the heated portion from the outside cold air.

In the modification shown in FIG. 10, instead of providing the heater 24 on the ice tray 12, the heater 24 is provided on the heat insulating portion 52 of the lid 50. The heater 24 is arranged so as to reciprocate in the front-rear direction in the heat insulating portion 52, and the partition walls 2 of the left and right ice making blocks 20, 20 are respectively provided on the outward path and the return path.
It is lined up on the left and right so as to heat the water surface in the vicinity of 2. The heater 24 is in contact with the bottom plate of the heat insulating part 52. Further, the lower surface of the heat insulating portion 52 and the upper surface of the partition wall 22 are in contact with each other. In addition, a heat insulating material 26 is provided inside the partition wall 22.
Are arranged to prevent cold air from entering the side surface of the ice making block 20 on the side of the partition wall 22 and prevent the heating effect of the heater 24 from being reduced.

In this modification, the heat generated by the heater 24 is
The ice tray 12 is passed through the contact portion between the heat insulating portion 52 and the partition wall 22.
And thereby heats the water surface in the vicinity of the partition wall 22 to obtain the same effect as that of the second example. Furthermore, in this modified example, since the heater 24 is provided in the heat insulating portion 52 that is wider than the partition wall 22, it is easy to dispose the heater 24, and since the heater 24 is provided in the lid 50, Unlike the ice tray 12, it is not twisted and deformed at the time of ice separation, and therefore the heater 24 can be easily protected.

[0070]

EFFECTS OF THE INVENTION With the ice making device of the present invention, when solidifying,
Since the gas component dissolved in water is forcibly released from the water surface to the outside by convection generated in the ice making block, the transparent ice can be made in a short time. In addition, since ice is made without applying mechanical external force such as vibration, minerals are hardly deposited, a complicated mechanical structure for vibration is not required, and there are few failures and excellent reliability. No noise is generated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an ice making device 10 according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an essential part of the ice making device 10.

3 is a plan view of the ice tray 12 of the ice making device 10. FIG.

4 (a) to 4 (c) are explanatory views for explaining a solidified state of the ice making device 10 in a transparent ice making mode.

5 is a graph showing the relationship between the temperature detected by the temperature sensor 30 and the ice making time in the transparent ice making mode of the ice making device 10. FIG.

FIG. 6A is a sectional view of an essential part of the ice making device 10 showing a modified example of the ice tray 12 of the first example, and FIG. 6B is a plan view of the ice tray 12;

FIG. 7A is a plan view of an essential part of an ice making device of a second example,
(B) is a sectional view of the main part.

FIG. 8 is a cross-sectional view of a main part of an ice making device according to a modification of the second example.

FIG. 9 is a cross-sectional view of an essential part of an ice making device according to another modification of the second example.

FIG. 10 is a cross-sectional view of an essential part of an ice making device according to still another modification of the second example.

11A to 11D are explanatory views for explaining a solidified state of water in a conventional ice making device.

FIG. 12 is a cross-sectional view of another conventional ice making device.

13A is a perspective view of ice produced by the ice making device of FIG. 12, and FIG. 13B is a sectional view thereof.

[Explanation of symbols]

 10 ... Ice making device 12 ... Ice tray 14, 50 ... Lid 20 ... Ice making block 22 ... Partition wall of ice tray 12 ... Heater 28 ... Control unit 30 ... Temperature sensor 46 ... Water 52 ... ... Insulation part of the lid 50

Claims (8)

[Claims] 1. An ice making device for supplying water to an ice tray made up of a plurality of ice making blocks to make ice for each ice making block, a lid for covering an upper surface of the ice making tray, and a lid provided on the ice making tray, An ice making device comprising: a heating unit that heats an upper portion of water supplied to the ice making block. 2. An ice making device that supplies water to an ice tray made up of a plurality of ice making blocks to make ice for each of the ice making blocks, wherein an upper portion of water provided to the ice making block and supplied to the ice making block is provided. It has a heating means for heating and a lid for covering a part of the upper surface of the ice making tray, and the lid is arranged close to above the water surface of the portion heated by the heating means. Ice making equipment. 3. The ice making device according to claim 1, wherein the heating means is attached to the back surface of the ice tray. 4. The ice making device according to claim 1, wherein the heating means is arranged close to the surface of the water supplied to the ice making block. 5. The ice-making device according to claim 1, wherein the ice-making blocks are arranged in two or more rows, and the heating means is arranged on a partition wall that partitions the rows. 6. An ice making device that supplies water to an ice tray made up of a plurality of ice making blocks to make ice for each ice making block, and a lid that covers a part of an upper surface of the ice making tray and is provided on the lid. An ice making device comprising: a heating means for heating a part of an upper surface of the ice making tray. 7. The ice making blocks are arranged side by side in two or more rows, the lid covers a partition wall separating the rows of the ice making blocks, and the heating means has an upper surface of water in contact with the partition walls. The ice making device according to claim 6, wherein the ice making device is heated. 8. During ice making, while cooling the ice making tray, the time when the operation of the heating means is started is detected to operate the heating means, and the water supplied to the ice making block comes close to the heating means. The control means for stopping the operation of the heating means and further continuing the cooling to complete the ice making when the solidification is detected except for the portion to be cooled, the method according to claim 1, 2, or 6. The ice-making device according to item 1.